Does a 'clean' label = a 'clean' product?. Credit: www.realbreadcampaign.org CC-BY-NC-SA-4.0
When is a preservative not a preservative?
When it’s a ‘clean label solution’.
Given the growing body of evidence linking UPFs (ultra-processed foods) with negative health outcomes, it's unsurprising that people are seeking out foods that are less processed, made with fewer E-numbers / additives.
Propionic acid, also known as E280, is classified as an additive and categorised as a preservative. It and its salts (E281-283) are commonly used by industrial dough fabricators to extend shelf life by inhibiting mould growth and other microbial activity.
In 2025, the Real Bread Campaign became aware that ‘clean label solutions’ suppliers were culturing flour with particular bacteria (such as Propionibacterium freudenreichii) that generate propionic acid. Those cultures can be used by industrial dough fabricators as a substitute for pure propionic acid to perform the same function.
Due to what we see as a legal loophole, however, manufacturers can choose to list it simply as ‘fermented wheat flour’, without mentioning the propionic acid. Such additions are known in the trade as 'label friendly'.
We found 'fermented wheat flour' listed in products made by / for the UK’s ten largest supermarket chains and six other high-profile industrial dough fabricators. Four of the 16 companies used a ‘no artificial preservatives’ assurance in their marketing, while one promised 'no preservatives' at all.*
On 21 August 2025, we asked the companies about the identity and purpose of the ‘fermented wheat flour’ in their products. Asda soon confirmed that it: ‘typically refers to flour fermented to generate propionic acid. This process is used to enhance flavour and shelf life, and it does not involve a live sourdough culture.’
After repeated questioning of the other 15 companies, Aldi and Tesco also advised that 'fermented wheat flour' was being added to extend shelf life by inhibiting mould growth.
One year on and we can report that the other 13 companies have been, erm, is ‘less forthcoming with a straight answer’ a good way of putting it?
* Though ‘fermented wheat flour’ is not classified in food legislation as a preservative, we do question the honesty and integrity of making such claims about a product manufactured with it. And that’s without considering the natural preservative properties of salt…
See also
Real Bread Campaign: Finding and sharing ways to make bread better for us, our communities and planet.
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